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534750 – Continental Motors OEM Magneto Gasket
Now Superseded by Part Number: 649954
Available now on the Airparts.aero Marketplace.
The 534750 is a critical sealing component engineered by Continental Aerospace Technologies (formerly Teledyne Continental Motors) for the interface between the ignition magneto and the engine accessory case. This gasket is designed to prevent engine oil from leaking out of the accessory housing while simultaneously blocking contaminants from entering the high-voltage environment of the magneto. It is a standard component for almost all Continental 360, 470, 520, and 550 series engines utilizing Bendix or Slick magnetos.
Continental has officially superseded the 534750 with Part Number 649954. This update introduces a more resilient, high-performance synthetic material that offers superior resistance to "thermal set." In high-performance piston engines, the magneto mounting flange is a high-heat zone; the modernized 649954 gasket is designed to remain flexible and effective through thousands of thermal cycles, ensuring a dry accessory case and reducing the risk of oil-fouled ignition components.
Key Features
High-Temperature Resilience: The 649954 material is specifically formulated to withstand the elevated temperatures of the accessory case without becoming brittle or "charred."
Oil & Chemical Resistance: Engineered to resist degradation from hot engine oil (mineral and ashless dispersant) and fuel vapors, preventing "wicking" or seal failure.
Optimized Compression: Designed to provide a uniform seal even if there are minute imperfections in the magneto mounting flange or the engine case.
Anti-Stick Coating: Features a surface treatment that prevents the gasket from bonding to the aluminum castings, allowing for clean removal during magneto timing or 500-hour inspections.
Standard Fitment: Maintains the exact dimensions of the legacy 534750, ensuring a 100% "drop-in" replacement for all applicable Continental engines.
Technical Specifications
Original Part Number: 534750
New Part Number: 649954
Manufacturer: Continental Aerospace Technologies (OEM)
Component Type: Magneto Mounting Gasket
Material: Modernized High-Temp Synthetic Fiber / Nitrile Composite
Thickness: Precision-calibrated per OEM specifications
Certification: FAA-PMA / OEM Original Equipment
Engine Compatibility
Continental IO-360 Series: (Including A, C, D, G, H, J, and K models)
Continental O-470 Series: (Including J, K, L, M, R, S, and U models)
Continental IO-520 Series: (Including B, BA, C, D, E, F, J, K, L, M, and N models)
Continental IO-550 Series: (Commonly found in Cirrus SR22, Beechcraft Bonanza, and Cessna 182/206/210)
Continental TSIO-520/550: (Turbocharged variants requiring enhanced thermal sealing)
Note: While this gasket fits the standard magneto flange, always verify the specific part call-out in your Illustrated Parts Catalog (IPC).
Applications
Magneto Installation: Used whenever a Bendix (S-20/S-1200) or Slick (4300/6300) magneto is mounted to the engine.
Magneto Timing Checks: Replaced whenever the magneto is loosened or removed to adjust internal or external timing.
Oil Leak Troubleshooting: A primary replacement item when oil is found weeping from the base of the magneto mounting flange.
Why Upgrade to 649954?
The magneto-to-engine interface is one of the most common sources of oil leaks in the accessory section. The 649954 (superseding 534750) provides a much higher level of dimensional stability. Legacy gaskets often shrank or "cold-flowed" over time, leading to loose mounting studs and oil seepage. The 649954 maintains its thickness and sealing pressure, which is critical for maintaining the proper Magneto-to-Engine Timing. If a gasket compresses unevenly or fails, it can slightly alter the position of the magneto, potentially impacting the ignition timing and engine performance.
Maintenance & Installation Addendum
Proper installation is the key to a leak-free ignition system.
Tech Tip: Before installation, ensure the mounting flange on both the magneto and the engine is clean and free of old gasket material. Use a plastic scraper to avoid gouging the aluminum.
Installation Note: This gasket should be installed dry. Avoid using RTV or other liquid sealants, as they can migrate into the accessory case or cause the gasket to "extrude" (squeeze out) when the mounting nuts are torqued. Always use new lock washers and torque the mounting nuts to the values specified in the Continental Maintenance Manual (typically 150–180 inch-pounds for standard studs).
Note: The 649954 is a flight-critical component. Any oil leakage in the vicinity of the magneto can be a fire hazard and can lead to internal magneto failure. Installation and magneto timing must be performed by a certified A&P mechanic.
